Sterilization test strip

Abstract

A compact sterilization indicator includes a wicking element having at least two different wicking rates across the length of the wicking element.

What is claimed is: 
     
       1. A sterilization indicator, comprising:
 a base element formed from a thermally conductive material having a length and a width, the base element having a recess formed therein extending along about a longitudinal centerline thereof, the recess formed within the base material less than the length and the width of the base material; 
 a first adhesive layer disposed on the base element; 
 an indicator chemical composition deposited in the recess; 
 a wicking element positioned at least in part in contact with the indicator chemical composition and positioned at least in part within the recess, the wicking element extending less than the length and width of the base element, wherein the wicking element includes a first zone, a second zone, and a third zone, wherein the first zone has a generally constant width W 38  and the third zone has a generally constant width W 40 , wherein W 38  is less than W 40 , wherein the second zone is arranged between the first zone and the third zone and has a width that increases from W 38  to W 40 , wherein a wicking rate across the first zone is greater than a wicking rate across the third zone, wherein the wicking element is arranged such that an end portion of the first zone is in contact with the indicator chemical composition; 
 a film layer positioned over the base element, the wicking element and the indicator chemical composition; 
 a paper layer disposed over the film layer; 
 a second adhesive layer disposed between the paper layer and the film layer, wherein the paper layer and the second adhesive layer include a window therein; and 
 an acceptance marker; 
 wherein, the indicator is configured to indicate that an acceptable level of sterilization has occurred when the indicator chemical composition wicks along the wicking element to a location beyond the acceptance marker after a sterilization process. 
 
     
     
       2. The sterilization indicator of  claim 1 , wherein the indicator chemical composition contains a temperature and steam sensitive material. 
     
     
       3. The sterilization indicator of  claim 1 , wherein the indicator chemical composition contains a dye. 
     
     
       4. The sterilization indicator of  claim 1 , wherein the film layer is formed from a cast polypropylene having a thickness of 2.0 to 2.2 mils. 
     
     
       5. The sterilization indicator of  claim 1 , wherein the film layer is formed from a cast polypropylene having a thickness of 3.0 to 3.2 mils. 
     
     
       6. The sterilization indicator of  claim 1 , wherein the base element formed from an aluminum foil. 
     
     
       7. The sterilization indicator of  claim 1 , wherein the base element is formed from an aluminum foil having a thickness of 3 mils. 
     
     
       8. The sterilization indicator of  claim 1 , wherein the first adhesive layer is formed from an acrylic adhesive. 
     
     
       9. The sterilization indicator of  claim 1 , wherein the second adhesive layer is formed from an acrylic adhesive. 
     
     
       10. The sterilization indicator of  claim 1 , wherein the wicking element is formed from a wicking paper having a basis weight of 66 g/m 2  to 186 g/m 2 . 
     
     
       11. The sterilization indicator of  claim 1 , wherein the wicking element is formed from a wicking paper having a thickness of 7.3 mil to 13.3 mil. 
     
     
       12. A sterilization indicator, comprising:
 a base element formed from a thermally conductive material having a length and a width, the base element having a recess formed therein extending along about a longitudinal centerline thereof, the recess formed within the base material less than the length and the width of the base material; 
 a first adhesive layer disposed on the base element; 
 an indicator chemical composition deposited in the recess; 
 a wicking element positioned at least in part in contact with the indicator chemical composition and positioned at least in part within the recess, the wicking element extending less than the length and width of the base element, wherein the wicking element includes at least two zones comprising a first zone and a second zone, wherein the first zone has a thickness greater than a thickness of the second zone; 
 a film layer positioned over the base element, the wicking element and the indicator chemical composition; 
 a paper layer disposed over the film layer; 
 a second adhesive layer disposed between the paper layer and the film layer, wherein the paper layer and the second adhesive layer include a window therein; and 
 an acceptance marker; 
 wherein, the indicator is configured to indicate that an acceptable level of sterilization has occurred when the indicator chemical composition wicks along the wicking element to a location beyond the acceptance marker after a sterilization process. 
 
     
     
       13. The sterilization indicator of  claim 12 , wherein the wicking element is formed from a layer of a wicking paper, wherein the first zone includes a second layer of a wicking paper. 
     
     
       14. A sterilization indicator, comprising:
 a base element formed from a thermally conductive material having a length and a width, the base element having a recess formed therein extending along about a longitudinal centerline thereof, the recess formed within the base material less than the length and the width of the base material; 
 a first adhesive layer disposed on the base element; 
 an indicator chemical composition deposited in the recess; 
 a wicking element positioned at least in part in contact with the indicator chemical composition and positioned at least in part within the recess, the wicking element extending less than the length and width of the base element, wherein the wicking element includes at least two zones comprising a first zone and a second zone, wherein the first zone is formed from a first wicking paper and the second zone is formed from a second wicking paper, wherein a wicking rate of the first wicking paper is greater than a wicking rate of the second wicking paper; 
 a film layer positioned over the base element, the wicking element and the indicator chemical composition; 
 a paper layer disposed over the film layer; 
 a second adhesive layer disposed between the paper layer and the film layer, wherein the paper layer and the second adhesive layer include a window therein; and 
 an acceptance marker; 
 wherein, the indicator is configured to indicate that an acceptable level of sterilization has occurred when the indicator chemical composition wicks along the wicking element to a location beyond the acceptance marker after a sterilization process. 
 
     
     
       15. A sterilization indicator, comprising:
 a base element formed from a thermally conductive material having a length and a width, the base element having a recess formed therein extending along about a longitudinal centerline thereof, the recess formed within the base material less than the length and the width of the base material; 
 a first adhesive layer disposed on the base element; 
 an indicator chemical composition deposited in the recess; 
 a wicking element positioned at least in part in contact with the indicator chemical composition and positioned at least in part within the recess, the wicking element extending less than the length and width of the base element, wherein the wicking element includes a first zone, a second zone, and a third zone, wherein a width of the first zone is less than a width of the third zone, wherein the second zone is arranged between the first zone and the third zone and has a width that increases from the width of the first zone to the width of the third zone, wherein the wicking element is position such that an end portion of the first zone is in contact with the indicator chemical composition, wherein the base element has a length of 1.75 inches to 4 inches, and the wicking element has a length of 1.125 inches to 1.625 inches, wherein the first zone has a width of 0.125 inches to 0.375 inches and the third zone has a width of 0.175 inches to 0.425 inches, wherein the width of the first zone is 0.03 inches to 0.07 inches less than the width of the third zone, wherein a criteria for the sterilization process is selected from 12 minutes at 121° C., 15 minutes at 121° C., 20 minutes at 121° C., 30 minutes at 121° C., 4 minutes at 132° C., 3.5 minutes at 134° C., 4 minutes at 134° C., 5 minutes at 134° C., 7 minutes at 134° C., and 3 minutes at 135° C.; 
 a film layer positioned over the base element, the wicking element and the indicator chemical composition; 
 a paper layer disposed over the film layer; 
 a second adhesive layer disposed between the paper layer and the film layer, wherein the paper layer and the second adhesive layer include a window therein; and 
 an acceptance marker; 
 wherein, the indicator is configured to indicate that an acceptable level of sterilization has occurred when the indicator chemical composition wicks along the wicking element to a location beyond the acceptance marker after a sterilization process. 
 
     
     
       16. The sterilization indicator of  claim 15 , wherein the indicator chemical composition contains a temperature and steam sensitive material, wherein the film layer is formed from a cast polypropylene having a thickness of 2.0 to 2.2 mils or a thickness of 3.0 to 3.2 mils, and wherein the wicking element is formed from a cotton wicking material having a basis weight of 186 g/m 2  and a thickness of 13.3 mil.